Kepler is more energy efficient, runs cooler and can steer up to 4 monitors.
It is very, very rare that a new generation is a step back from the older generation.
Your confusion is probably caused by the fact that Tom's benchmarking is directed at gaming and synthetic performance, not at AE and PR performance. And the LegitReview is solely comparing AE Ray tracing performance when using multiple video cards compared to single video cards. There is no comparison for PR CS6, which only can use a single GPU. See MPE Performance but you have to be registered and logged in to access this page. For some further info, look at Latest News and scroll down the page to see a limited comparison on video card performance on the same system.
I am very excited for premiere CC and its multiple cuda utilization for rendering..
Dual video card support is nice, but you have to remember these wise words from the blind man:
"I've got to see it, before I believe it."
You may know that I'm often using systems that others consider extravagant, overkill, way too costly, etc. and even though I am a bit tempted to try out a second video card like the GTX Titan as an addition to my GTX 680/4G (OC) card, my reservations are: 'Is it worth the considerable expense...?' and currently my gut feeling is that the benefit will be so marginal for me with the applications I use mainly, that it would be a waste of money.
There is always something newer and faster than what you or I have, but is it worth it? That is the question. If one has an outdated system and is in dire need of a new system, then these considerations may come into play, but for recent systems based on the 2011 platform (1155 platforms are out of question due to the lack of PCIe lanes) it will be hard to justify the extra cost for an additional video card, especially since all 6xx+ cards support up to 4 monitors.
ive always been trying to build myself the fastest editing machine i could for my work, this one was built 12months ago and i have upgraded the ram to 32since.. but there is that constant wanting the fastest that i think we all have, and your right you have to decide - "if i buy that fastest gfx card i can for £900 will it actually increase my productivity to justify the spend"
Im quite excited to try this spare 285 or use the 460 in conjunction with a 6xx series maybe for faster rendering, seeing as its only £50 for a 2nd hand 285 - ill definetly be doing some benchmarking with/without 2 cuda cards when its supported.
Ive always been happy with the timeline performance of premiere cuda on my 285 or 460 cs5/6 even with effects, dropping mpe to 1/2 gives realtime playback on full hd with multiple colorista2/sharpen/etc effects and other things happening so that is good.
Its the rendering that has always niggled me and thanks to the ppbm threads that could be sorted too!
anyhow i shall stop stealing the thread!